radiator light comes on.. a lot
 

i have an 06 rx8, my coolant low indicator light comes on very frequently, but the coolant is not low in the resevoir. any sugestions? maybe its a bad sensor? any help would be greatly appreciated!

Mine did this for about a week but eventually went away... even though it didn't say it was low, I opened it up (while cool) and added just a tad bit more. Haven't had the light flash since. Good luck!

common issue and a search will turn up your answers

There is a DIY how to clean the sensor

Common failure of the coolant overflow tank sensor. Clean it as described above in the DIY section.

Mine pop up due to air bubbles in coolant lines.

Long winded thread, but the data and answers are in there.

https://www.rx8club.com/series-i-trouble-shooting-95/coolant-bottle-greatest-secrets-revealed-182793/

Here's the bottom line:

www.mazmart.com was running a special on the bottle here recently, don't know if they still are or not.
The sensor is integral to the bottle, so you can't just buy the sensor.
Direct bottle link = http://www.mazmart.com/ItemDetail.aspx?id=531

If you have the low coolant light and don't want to replace the bottle, then you can just unplug the sensor and check your coolant often. I think I would wrap the PCM side of the connector that will be dangling with electrical tape or something in order to keep it dry(and keep crud out) because if the two terminals or wiring short on that side, you are going to get a coolant light. See just about the last post in the thread above for a pic of where to unplug it if not sure.

Now, you could also just take the bottle out and fill it with White Vinegar for the night, then shake the hell out of it, flush it out real good with water, and then put it back in. Some have had luck with that.

The gritty details are in the thread I linked as I went way over the top in my experiments!